Efficient space utilization using lightweight structures is very important for operators of aircrafts seeking to maximize revenue, especially with rising costs for aircraft fuel and increased emphases on fuel use efficiency. Besides optimization of the passenger cabin and luggage handling requirements, stowage and rest space for flight and cabin crew must also be provided with minimal impact to passenger cabin floor area (and seat count) while avoiding loss of revenue belly cargo capacity. As use of longer-range passenger aircrafts on routes with flight durations requiring rest periods for flight crew and cabin attendants increases over time, the need for providing dedicated rest facilities and space for other main cabin passenger service functions has become much more important.
A promising area for efficient space utilization is the overhead space in twin-aisle aircraft for pilot and attendant crew rest units. Long range flights may require a replacement crew as mandated by FAA regulations. The replaced crew is required to be off duty (‘at rest’) a specified number of hours between shifts, so an arrangement must be made to facilitate this requirement. This may be done by providing a rest/sleep area reserved especially for the use of the crew. Such areas have been previously used above, below and on the main deck. In order to use as much of the area in an aircraft to generate revenue, airlines prefer to dedicate the area below the main deck to transport cargo and the main deck for fare paying passengers. This leaves the area above the main deck as a good and practicable location for the crew to rest.
As there is only a discrete amount of space above the passenger cabin where a crew rest can be placed, this area must be maximized for the comfort of the crew while still allowing necessary systems passageway through the aircraft. Fitting a structure in this area may be somewhat cumbersome and may lead to less than optimal weight-efficient designs. Current overhead crew rests may consist of many flat and curved panels fastened and bracketed together to create a structure for two or more flight crew to rest and sleep. The sleeping quarter structure typically has a rectangular footprint with square edges going up to a curved ceiling that follows the curvature of the fuselage crown. The existing designs may be non-optimized with regards to space utilization, overall weight performance, manufacturability, etc., and may require manual assembly of many pieces to fabricate the structure. The typical assembly requires the use of a large quantity of fasteners and metallic brackets, which may cause the crew rests to be particularly heavy for the function that they perform. This extra weight may require being supported with strong (and heavy) fittings. All of these details add to the overall weight of the aircraft. The more weight that is added to the aircraft, the less efficient the aircraft.
Accordingly, there is a need for an efficient solution for overhead space utilization that uses fewer panel structures and fasteners and is suitably configured to better utilize and conform to the available space in the fuselage crown area.